Protocol 2
Simplified Cardiovascular Management Study (SimCard): A Cluster-Randomized Trial to Evaluate the Effects of a Simplified Cardiovascular Management Program in Tibet, China and Haryana, India

Objectives

Protocol 1
To evaluate the effects of: 1) a simple low-cost cardiovascular disease (CVD) prevention and control package, delivered by village doctors, on the proportion of individuals at high risk for CVD that are identified and appropriately managed and their mean blood pressure levels; 2) a community-based salt reduction and health promotion program, delivered by community health educators, on mean blood pressure levels of village older adults.

Protocol 2
To evaluate the effects of implementing a simple low cost cardiovascular management program for high-risk individuals, delivered by primary care providers and village doctors, including the proportion of patients appropriately treated with diuretics and aspirin.

Background

Cardiovascular disease is the leading cause of death and disability worldwide, with particular burden in low and middle income countries highlighting the need for effective interventions that are affordable, applicable and effective in these settings. In particular, clinical guidelines recommend a combined strategy of lifestyle modifications and appropriate medication use for CVD prevention and control in individuals at high CVD risk. However, further evidence is needed to evaluate the population benefits from implementing these high risk strategies, particularly in resource poor settings where targeting high risk individuals could be a cost effective approach.

Protocol 1
Rural China is underdeveloped and has more limited healthcare resources compared to urban areas. The lowest level healthcare facility is the village clinic which typically serves a population between 300 and 2,500 residents. The primary care health services are provided by “village doctors” who are not qualified physicians by Western standards but are healthcare workers with limited medical training, basic equipment and a restricted pharmacopeia. Strategies that enable this workforce to deliver appropriate cardiovascular care to those at high risk have the potential to reduce the disease burden in these resource poor settings.

Stroke is the leading cause of death in China. Excess sodium intake is a key determinant of high blood pressure, the leading cause of stroke. China, especially in the rural areas, has one of the highest sodium intake levels in the world mainly from salt added in cooking and condiments at home. The substitution of salt with an alternate product lower in sodium may provide the opportunity to deliver a large public health benefit at low cost. Beneficial effects of salt substitution on urinary electrolytes and blood pressure have been achieved in randomized trials done in selected populations including those in rural China, but whether effects can be achieved in the general community was unknown at the time of the study.

Protocol 2
China and India face similar challenges and opportunities in CVD prevention and control such as the rising CVD burden, large urban-rural health disparities, limited resources and capacity, a large population base, and increasing access to mobile phones. Previous studies have shown that there are significant improvements in accessing healthcare facilities, disease screening and monitoring, and patients’ adherence to treatment by engaging community healthcare workers (CHWs). The high penetration of cell phones even in resource poor settings offers an unprecedented opportunity to provide support to CHWs. Therefore, the SimCard study aimed to develop and evaluate a simplified yet guideline-based multifaceted intervention program for CVD management of high risk individuals delivered by CHWs with the aid of a mobile technology based electronic decision support system.

Subjects

Protocol 1
120 rural villages from 10 counties in 5 provinces/autonomous regions (Hebei, Liaoning, Ningxia, Shanxi and Shaanxi) in northern China were selected to participate. Two counties from each province were selected to broadly represent the socioeconomic development of the region. 12 townships in each county were selected based on their willingness to participate and proximity to county centers. One village from each township was selected in such a way to maximize the geographic distance between participating villages.

Protocol 2
27 villages from 15 townships in two counties of Tibet, China and 20 villages from one tehsil in Haryana State, India participated in the study. Villages from both countries were selected based on the eligibility criteria of having: 1) a high CVD burden within the region, 2) limited healthcare resources, 3) existing CHWs or qualified candidates who can be trained to fulfil their role, and 4) local government support. The average population size of the villages in the trial was 900 in China and 3,500 in India.

Design

Protocol 1
The China Rural Health Initiative (CRHI) included two main interventions: 1) the Primary Care Provider project used a primary care based high CVD risk management package delivered by village doctors, and 2) the Sodium Reduction Study used a community based salt reduction program delivered mainly by community health educators. Participating villages were randomly assigned into 4 equal groups: no intervention, sodium reduction intervention only, primary care intervention only, and both interventions.

In the Primary Care Provider project, village doctors in the intervention group were trained by physicians from the regional county hospital and certified to implement the intervention program for identifying and managing patients with high CVD risk. Training occurred once before the intervention and then again approximately one month after initiation of the intervention. Patients were defined as being high risk if they meet one or more of the following criteria: 1) history of coronary heart disease or stroke, or 2) older age (men ≥ 50 years and women ≥ 60 years) with history of diabetes, or 3) older age with systolic blood pressure (SBP) ≥ 160 mmHg. Identified patients were to receive monthly follow-up where the village doctor would initiate blood pressure lowering medications if SBP was ≥ 140 mmHg, initiate low dose aspirin when SBP < 160 mmHg and not contraindicated, provide lifestyle advice, and encourage use of other evidence based medications where appropriate. The primary outcome was change in mean SBP.

In the Sodium Reduction Study, health education was delivered in the intervention villages by the township health educators through public lectures, the display and distribution of promotional materials, and special interactive education sessions targeted towards individuals at elevated risk of vascular diseases. Additionally, a reduced-sodium, added-potassium salt substitute was made available at village shops and promoted through the health education component of the intervention. Intervention villages were further randomized in a 1:1 ratio to receive subsidization of the price of the salt substitute. The primary outcome was change in 24-hour urinary sodium excretion, measured as a proxy for salt intake.

In both studies, control villages received no intervention and continued usual practices. Surveys of a random subset of adults in each village were performed at baseline and at the end of the intervention period. The survey included a brief interviewer-administered questionnaire, measurement of blood pressure, height and weight, and the collection of a 24-hour urine sample.

Protocol 2
Participating villages were randomized to intervention or control with stratification by country. The intervention was developed as a simplified version of international and national clinical guidelines for CVD management. The key elements of the intervention consisted of two therapeutic lifestyle modifications (smoking cessation and salt reduction) and the appropriate prescription of two medications (blood pressure lowering agents and aspirin). The blood pressure lowering agent was a low-dose hydrochlorothiazide (12.5 mg/day) in China, and a calcium channel blocker (2.5 or 5 mg/day) in India. The recommended dose for aspirin was 75-100 mg/day. All hypertensive patients (SBP ≥ 140 mmHg) without contraindications would be prescribed the antihypertensive medication with a treatment target of 140 mmHg or lower while only patients with coronary heart disease, ischemic stroke, and diabetes but without contraindications such as bleeding or high blood pressure (SBP ≥ 160 mmHg) would be prescribed aspirin.

The management program was delivered by trained CHWs in the intervention group on a monthly basis with the assistance of an electronic decision support system in the form of an Android based smartphone application. It consisted of prompts regarding the patient’s current lifestyle habits, blood pressure measurements, current medication use, previous medical history, new conditions, contraindications, and side effects. CHWs received a one day training session prior to the start of the intervention and refresher training every 3-4 months during the intervention.

In the control group, usual CVD management programs continued without additional intervention. However, in India, as stipulated by the ethics committee, the medications used in the intervention arm were also made available free of charge to patients in the primary care facilities serving the control villages.

The primary outcome was the net difference between groups in the change in the proportion of patient reported antihypertensive medication use from baseline to one year follow-up.

Conclusions

Protocol 1
Results are not yet published for the Primary Care Provider project. For the Sodium Reduction Study, the intervention villages showed significant decreases in urinary sodium excretion, decreases in the urinary sodium to potassium ratio, and increases in urinary potassium as compared to control villages, most likely due to increased use of the salt substitute. The use of the salt substitute in villages with a subsidy was almost twice that of villages without the price subsidy. Intervention effects on blood pressure were modest, but non-significant.

Yan LL, Fang W, Delong E, et al. Population impact of a high cardiovascular risk management program delivered by village doctors in rural China: design and rationale of a large, cluster-randomized controlled trial. BMC Public Health. 2014;14:345. doi:10.1186/1471-2458-14-345.

Protocol 2
Compared with the control group, the intervention group had a significantly higher net increase in the proportion of patients using antihypertensive medication. The results indicate that the simplified cardiovascular management program improved quality of primary care and clinical outcomes in resource poor settings in China and India. Larger trials in more places are needed to ascertain potential impacts on mortality and morbidity outcomes.

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